Ventilation system

ABSTRACT

A ventilation system for a building has blowers installed in a number of rooms for occupation, for blowing fresh outside air directly into said rooms. There is a central extractor and with the aid of a control device, the amount of air blown in is controlled for each of the rooms as required. Connection of the various components described above is via the mains network.

The present invention relates to a ventilation system for a building. Numerous ventilation systems are known in the state of the art. A first system is that in which air is extracted from the various rooms by a central unit and, optionally with the addition of further air originating from the environment, is blown back into the rooms. Such a system can be used only for somewhat larger buildings and demands appreciable structural modifications.

A further system consists in the use of a single extractor in which a fan has been fitted. Ventilation openings are made in the various rooms of the building. If these ventilation openings are made relatively large, it can be guaranteed under all circumstances that a flow of air from the various rooms to the outside takes place via the central extractor. However, this requires that the central extractor has an appreciable power and extraction is also accompanied by the loss of an appreciable proportion of the heat. The latter can be compensated by installing a heat exchanger in the central extractor, but this is associated with appreciable technical and practical problems.

U.S. Pat. No. 4,742,475 discloses an air control system for a non-compartmentalised building, such as a greenhouse, wherein there is a feed system with fan and heating in the ridge, whilst a ventilation window is fitted in the side wall. There can also be an extractor fan. In WO 01/25695 a ventilation system is described wherein air that has been blown out is fed over a heat accumulator and the heat stored therein is recovered again at a later stage.

The aim of the present invention is to provide a ventilation system for a building that is relatively simple to implement. It must be possible to use this system easily both in new buildings and in existing buildings. On the other hand, the system must always guarantee that sufficient air is introduced into the various rooms. On the other hand, in order to be sufficiently comfortable and as far as possible to prevent heat losses, not too much air must be introduced. That is to say, the aim is to provide a minimal ventilation system so that there is no more ventilation than is necessary in order to maintain the desired climate in the building.

This aim is realised with a ventilation system for a building comprising at least two air blowers with adjustable flow rate, which only blow in air, each to be connected by an inlet to the outside air and to be installed in different rooms in said building, as well as a single air extractor which only blows out air and is to be installed in a further room in said building, and a control device for mutual control of said air blowers and air extractor, wherein said system is embodied for minimal ventilation and has measurement means for measuring the quantity of incoming and outgoing air, said measurement means being connected to said control device for controlling said air blowers and/or said air extractors.

It has been found that for a minimal ventilation system it is essential that the amount of air that enters and/or the amount of air that is extracted is accurately known. In particular, according to the invention in the case of a building with various rooms there will be at least one air blower in each room and the climate in each room (or group of rooms) is individually controlled on the basis of the climatic conditions prevailing there. With this arrangement as small as possible an amount of air is supplied in order to maintain the desired climate.

Because only very small amounts of air are moved in the building it is no longer necessary to take special measures to restrict the heat loss as far as possible. Consequently, it is not necessary to use complex constructions for heat recovery. More particularly, with the present invention it is possible to dispense with a heat exchanger in the air extractor that warms up air that has just been drawn in from outside, immediately or later. As a result it is possible to set up a ventilation system in a completely different way, that is to say with a central air extractor, the position of which is completely independent of the air blower. It is possible accurately to determine the amount of air introduced/extracted only by measurement. Such a measurement can be implemented using any construction known in the state of the art, for example using air speed meters and the like. It is also possible to determine the resistance of the fan motor in the air in the manner described below and to draw conclusions with regard to the flow rate on the basis of this determination.

Although separate cables can be used when linking the various components, according to an advantageous embodiment of the invention the control device is provided with means for converting the control signal into a signal to be transported by a mains supply and to provide the blowers with means for converting a signal received from the control device from the mains supply to a control signal for said blowers.

According to the present invention a connection between a controller and the various blowers is provided with the aid of multiplexing techniques. According to the invention these blowers are active mechanically operating fans. By drawing in air directly from the outside, it is possible to provide a continually adjusting control. The amount of air drawn in from outside can be controlled depending on, for example, weather conditions, but also on conditions in the various rooms. Because the various components operate via the mains, complex separate wiring is not necessary.

If the building concerned has various phases in the mains, a coupling has to be made, preferably in the meter cupboard, for the connections for the various signals superimposed on the mains for controlling the blowers. Furthermore, measures can be taken to prevent measurement/control signals being introduced into or received from the network upstream of the meter cupboard.

By means of the present invention it is possible for a relatively low flow rate to suffice for air movement in each of the rooms. However, this flow rate is just adequate under all circumstances.

By means of this system, which enables very accurate adjustment to the various actually prevailing conditions, it is possible to ventilate with a relatively small amount of air, as a result of which the heat losses are negligible. Of course, it is always possible to use heat exchangers in the extractor.

It is possible to input the “way of life” to be expected in the relevant rooms of the building into the control device. For instance, towards mealtimes there will be a larger number of people in the kitchen than later in the evening. A bedroom will be occupied only at night and a living room during the day. Depending on this pattern and the number of people to be expected, the ventilation flow rate for each of the rooms can be individually specified beforehand and corrected by the user if necessary.

According to an advantageous embodiment of the invention it is also possible to control the extractor by means of the control device. This is possible either via a separate cable, which in general will be present, or by means of the multiplexing technique described above.

In order to optimise the control in the various rooms, according to an advantageous embodiment there are sensors in the various rooms. These measure the conditions prevailing therein. An important factor is the percentage of CO₂. This is a measure for the number of people and the activity of those people who are in a specific room. It is easily possible to measure this percentage and on the basis thereof to admit more or less air from the outside. It is also possible to determine other parameters in certain rooms, such as the humidity in a kitchen. Moreover, a signal can be given manually to the control device if, for example, additional build-up of moisture is to be expected in the kitchen during cooking. For this purpose there can be a switch in the vicinity of, for example, the extractor. Another important parameter is, as indicated above, the wind speed acting on the building. By measuring the air speed at the location of the blower, the flow rate can be corrected, that is to say the blower can start to run at a higher or lower rate. If the wind is blowing onto the blower, the energy supplied will become less and if the wind is blowing away from this a higher speed of revolution or more work on the part of the fan concerned will be required. This control by means of sensors can be independent of or combined with the control based on ways of life described above.

Moreover, other data can also be input into the control device in order to make this specific for the buildings concerned.

The invention also relates to a building containing the ventilation system described above.

The extractor is preferably connected to the wet cells of the building. Examples are toilets, showers, bathrooms and kitchens.

If the installation is used in relatively cold climates, it is preferable to warm the incoming air to avoid the sensation of draught as far as possible. Preferably, the air is not warmed to above room temperature, but preferably to a temperature of at most 16° C.

As indicated above, it is possible to fit the air extractor in any arbitrary position, because there is no longer any relationship with the air blower with regard to heat recovery. However, it is possible to recover heat at the location of the air extractor for another use, such as, for example, a heat pump boiler.

The invention also relates to a method for ventilating a building, wherein air is mechanically blown into a number of rooms directly form the outside and air is mechanically extracted to the outside from at least one room, wherein the speed of air blown in is determined per blowing-in point and the mechanical work for blowing in is increased or reduced depending on this determination.

The invention will be explained in more detail below with reference to an illustrative embodiment shown in the drawings. In the drawings:

FIG. 1 shows, diagrammatically, a building provided with the system of the invention.

In FIG. 1 a building is indicated by 1. The blowers are indicated diagrammatically by 2. Various sockets are indicated by 3. The attic floor of the building is provided with a mains network 28, the first floor with mains network 9 and the ground floor with mains network 10. These mains network are on different phases and come together in the meter cupboard 4. An extractor 7 has been installed in the top of the building. This provides extraction for, inter alia, a shower room 8. Via the various chinks between doors and the like, extraction from the shower room 8 results in a reduced pressure in the building. However, this is negated by the action of the blowers 2. Control of the blowers 2 takes place with the aid of a control unit or central controller 6. This is likewise connected to the mains network 9. This connection of the controller 6 and of the blowers 2 to the mains network is the only connection. With the aid of the multiplexing technique it is possible to control the speed of revolution of the blowers 2 and, respectively, the flow rate thereof with the controller 6. Separate wiring is not required.

There is an air speed sensor 11 in each blower 2. The signal received by this sensor is transferred by a multiplexing technique to the controller 6. CO₂ sensors are indicated by 12 and are located in the most frequented rooms. These sensors can be combined with blowers 2 or installed separately.

By means of these CO₂ sensors it is possible to check whether there is adequate fresh air in a room. If this amount is inadequate, the relevant blower 2 will be activated by the controller 6. A desired amount of air input is determined by this controller 6. By measuring the air speed in the fan channel of blower 2 it is possible to determine directly whether the requirements imposed by the controller are met and to make adjustments if necessary.

In this way it is possible very accurately to ventilate the requisite amount of air into a room per unit time. It is thus possible to comply with the standards imposed by the various authorities, such as NEN 1087. As a result of the use of blowers that operate actively it is necessary only to use ventilation gratings with an effective cross-sectional surface area that corresponds to the most unfavourable situation.

It will be understood that the combination of radiator and blower fan shown here can also be used with other heating and air control systems, that is to say it does not necessarily have to be used exclusively with the system according to the present invention as described above.

It will be understood that the air blower can comprise any known construction, such as the Sonair blower marketed by Innosource. It is also possible to fit a wide variety of types of filters, ionisers and the like in the air blower.

Further variants that fall within the scope of the appended claims will occur immediately to those skilled in the art on reading the above. 

1-14. (canceled)
 15. A ventilation system for a building comprising at least two air blowers, each provided with a motor, with adjustable flow rate, which only blow in air, each to be connected by an inlet to the outside air and to be installed in different rooms in said building, as well as a single air extractor, provided with a motor, which only blows out air and is to be installed in a further room in said building, and a control device for mutual control of said air blowers and air extractor, wherein said system is adapted to provide minimal ventilation and has measurement means for measuring the quantity of incoming and outgoing air, said measurement means being connected to said control device for controlling said air blowers and/or said air extractors.
 16. The ventilation system according to claim 15, wherein the control device is provided with means for converting the control signal into a signal to be transported by a mains supply and to provide the blowers with means for converting a signal received from the control device from the mains supply to a control signal for said blowers.
 17. The ventilation system according to claim 15, further including sensors which are to be installed in said building and are provided with means for converting the sensor signal into a signal to be transported by the mains supply and wherein said control device is provided with means for converting the signal received from the sensors from the mains supply into an input signal for said control device.
 18. The ventilation system according to claim 17, wherein said sensors are CO₂ sensors.
 19. The ventilation system according to claim 17, wherein said sensors are air speed sensors and are accommodated in said air blower/extractor.
 20. The ventilation system according to claim 15, wherein said control device is provided with input means for inputting building-specific data.
 21. The ventilation system according to claim 15, wherein said air blower comprises an air inlet part, a fan part and an air discharge part, wherein the air discharge part or air inlet part contains a heating element.
 22. The ventilation system according to claim 21, wherein said inlet part has a first part that is suitable for fitting through a wall of a building and has a second part that extends essentially vertically.
 23. The ventilation system according to claim 15, wherein said control device provides that essentially the same amount of air is extracted by said air extractor as is introduced by said air blowers.
 24. A building containing a ventilation system comprising at least two air blowers, each provided with a motor, with adjustable flow rate, which only blow in air, each to be connected by an inlet to the outside air and to be installed in different rooms in said building, as well as a single air extractor, provided with a motor, which only blows out air and is to be installed in a further room in said building, and a control device for mutual control of said air blowers and air extractor, wherein said system is adapted to provide minimal ventilation and has measurement means for measuring the quantity of incoming and outgoing air, said measurement means being connected to said control device for controlling said air blowers and/or said air extractors, wherein said blowers are installed in rooms for occupation.
 25. The building according to claim 24, wherein said extractor is connected to a wet cell.
 26. The building according to claim 24, wherein said air blower comprises an air inlet part, a fan part and an air discharge part, wherein the air discharge part or air inlet part contains a heating element, wherein the air inlet is installed immediately underneath a sill (threshold) in said building.
 27. A method for ventilating a building, wherein air is mechanically blown directly into a number of rooms from the outside and air is mechanically extracted to the outside from at least one room, wherein the speed of air blown in is determined per blowing-in point and the mechanical work for blowing in is increased or reduced depending on this determination.
 28. The method according to claim 27, wherein the CO₂ concentration is measured in said rooms wherein more outside air is blown in when said concentration in said room concerned becomes higher. 